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29 * @(#)fs.h 8.13 (Berkeley) 3/21/95
30 * $FreeBSD: src/sys/ufs/ffs/fs.h,v 1.14.2.3 2001/09/21 19:15:22 dillon Exp $
31 * $DragonFly: src/sys/vfs/ufs/fs.h,v 1.6 2008/08/04 18:15:47 dillon Exp $
34 #ifndef _VFS_UFS_FS_H_
35 #define _VFS_UFS_FS_H_
38 * Each disk drive contains some number of filesystems.
39 * A filesystem consists of a number of cylinder groups.
40 * Each cylinder group has inodes and data.
42 * A filesystem is described by its super-block, which in turn
43 * describes the cylinder groups. The super-block is critical
44 * data and is replicated in each cylinder group to protect against
45 * catastrophic loss. This is done at `newfs' time and the critical
46 * super-block data does not change, so the copies need not be
47 * referenced further unless disaster strikes.
49 * For filesystem fs, the offsets of the various blocks of interest
50 * are given in the super block as:
51 * [fs->fs_sblkno] Super-block
52 * [fs->fs_cblkno] Cylinder group block
53 * [fs->fs_iblkno] Inode blocks
54 * [fs->fs_dblkno] Data blocks
55 * The beginning of cylinder group cg in fs, is given by
56 * the ``cgbase(fs, cg)'' macro.
58 * The first boot and super blocks are given in absolute disk addresses.
59 * The byte-offset forms are preferred, as they don't imply a sector size.
63 #define BBOFF ((off_t)(0))
64 #define SBOFF ((off_t)(BBOFF + BBSIZE))
65 #define BBLOCK ((ufs_daddr_t)(0))
68 * Addresses stored in inodes are capable of addressing fragments
69 * of `blocks'. Filesystem blocks of at most size MAXBSIZE can
70 * be optionally broken into 2, 4, or 8 pieces, each of which is
71 * addressable; these pieces may be DEV_BSIZE, or some multiple of
74 * Large files consist of exclusively large data blocks. To avoid
75 * undue wasted disk space, the last data block of a small file may be
76 * allocated as only as many fragments of a large block as are
77 * necessary. The filesystem format retains only a single pointer
78 * to such a fragment, which is a piece of a single large block that
79 * has been divided. The size of such a fragment is determinable from
80 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
82 * The filesystem records space availability at the fragment level;
83 * to determine block availability, aligned fragments are examined.
87 * MINBSIZE is the smallest allowable block size.
88 * In order to insure that it is possible to create files of size
89 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
90 * MINBSIZE must be big enough to hold a cylinder group block,
91 * thus changes to (struct cg) must keep its size within MINBSIZE.
92 * Note that super blocks are always of size SBSIZE,
93 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
98 * The path name on which the filesystem is mounted is maintained
99 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
100 * the super block for this name.
102 #define MAXMNTLEN 468
105 * The volume name for this filesystem is maintained in fs_volname.
106 * MAXVOLLEN defines the length of the buffer allocated.
111 * There is a 128-byte region in the superblock reserved for in-core
112 * pointers to summary information. Originally this included an array
113 * of pointers to blocks of struct csum; now there are just three
114 * pointers and the remaining space is padded with fs_ocsp[].
116 * NOCSPTRS determines the size of this padding. One pointer (fs_csp)
117 * is taken away to point to a contiguous array of struct csum for
118 * all cylinder groups; a second (fs_maxcluster) points to an array
119 * of cluster sizes that is computed as cylinder groups are inspected,
120 * and the third points to an array that tracks the creation of new
123 #define NOCSPTRS ((128 / sizeof(void *)) - 3)
126 * A summary of contiguous blocks of various sizes is maintained
127 * in each cylinder group. Normally this is set by the initial
128 * value of fs_maxcontig. To conserve space, a maximum summary size
129 * is set by FS_MAXCONTIG.
131 #define FS_MAXCONTIG 16
134 * MINFREE gives the minimum acceptable percentage of filesystem
135 * blocks which may be free. If the freelist drops below this level
136 * only the superuser may continue to allocate blocks. This may
137 * be set to 0 if no reserve of free blocks is deemed necessary,
138 * however throughput drops by fifty percent if the filesystem
139 * is run at between 95% and 100% full; thus the minimum default
140 * value of fs_minfree is 5%. However, to get good clustering
141 * performance, 10% is a better choice. hence we use 10% as our
142 * default value. With 10% free space, fragmentation is not a
143 * problem, so we choose to optimize for time.
146 #define DEFAULTOPT FS_OPTTIME
149 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
150 * tune the layout preferences for directories within a filesystem.
151 * His algorithm can be tuned by adjusting the following parameters
152 * which tell the system the average file size and the average number
153 * of files per directory. These defaults are well selected for typical
154 * filesystems, but may need to be tuned for odd cases like filesystems
155 * being used for squid caches or news spools.
157 #define AVFILESIZ 16384 /* expected average file size */
158 #define AFPDIR 64 /* expected number of files per directory */
161 * The maximum number of snapshot nodes that can be associated
162 * with each filesystem. This limit affects only the number of
163 * snapshot files that can be recorded within the superblock so
164 * that they can be found when the filesystem is mounted. However,
165 * maintaining too many will slow the filesystem performance, so
166 * having this limit is a good idea.
168 * VALUE NOT IMPLEMENTED IN DragonFly(and very unlikely to ever be as there are
169 * much better options such as journaling), RESERVED FROM FreeBSD 5.x SO
170 * SUPERBLOCKS REMAIN COMPATIBLE FOR THE TIME BEING. WHY ARE WE YELLING ?
175 * Per cylinder group information; summarized in blocks allocated
176 * from first cylinder group data blocks. These blocks have to be
177 * read in from fs_csaddr (size fs_cssize) in addition to the
181 int32_t cs_ndir; /* number of directories */
182 int32_t cs_nbfree; /* number of free blocks */
183 int32_t cs_nifree; /* number of free inodes */
184 int32_t cs_nffree; /* number of free frags */
188 * Super block for an FFS filesystem.
191 int32_t fs_firstfield; /* historic filesystem linked list, */
192 int32_t fs_unused_1; /* used for incore super blocks */
193 ufs_daddr_t fs_sblkno; /* addr of super-block in filesys */
194 ufs_daddr_t fs_cblkno; /* offset of cyl-block in filesys */
195 ufs_daddr_t fs_iblkno; /* offset of inode-blocks in filesys */
196 ufs_daddr_t fs_dblkno; /* offset of first data after cg */
197 int32_t fs_cgoffset; /* cylinder group offset in cylinder */
198 int32_t fs_cgmask; /* used to calc mod fs_ntrak */
199 ufs_time_t fs_time; /* last time written */
200 int32_t fs_size; /* number of blocks in fs */
201 int32_t fs_dsize; /* number of data blocks in fs */
202 int32_t fs_ncg; /* number of cylinder groups */
203 int32_t fs_bsize; /* size of basic blocks in fs */
204 int32_t fs_fsize; /* size of frag blocks in fs */
205 int32_t fs_frag; /* number of frags in a block in fs */
206 /* these are configuration parameters */
207 int32_t fs_minfree; /* minimum percentage of free blocks */
208 int32_t fs_rotdelay; /* num of ms for optimal next block */
209 int32_t fs_rps; /* disk revolutions per second */
210 /* these fields can be computed from the others */
211 int32_t fs_bmask; /* ``blkoff'' calc of blk offsets */
212 int32_t fs_fmask; /* ``fragoff'' calc of frag offsets */
213 int32_t fs_bshift; /* ``lblkno'' calc of logical blkno */
214 int32_t fs_fshift; /* ``numfrags'' calc number of frags */
215 /* these are configuration parameters */
216 int32_t fs_maxcontig; /* max number of contiguous blks */
217 int32_t fs_maxbpg; /* max number of blks per cyl group */
218 /* these fields can be computed from the others */
219 int32_t fs_fragshift; /* block to frag shift */
220 int32_t fs_fsbtodb; /* fsbtodb and dbtofsb shift constant */
221 int32_t fs_sbsize; /* actual size of super block */
222 int32_t fs_csmask; /* csum block offset (now unused) */
223 int32_t fs_csshift; /* csum block number (now unused) */
224 int32_t fs_nindir; /* value of NINDIR */
225 int32_t fs_inopb; /* value of INOPB */
226 int32_t fs_nspf; /* value of NSPF */
227 /* yet another configuration parameter */
228 int32_t fs_optim; /* optimization preference, see below */
229 /* these fields are derived from the hardware */
230 int32_t fs_npsect; /* # sectors/track including spares */
231 int32_t fs_interleave; /* hardware sector interleave */
232 int32_t fs_trackskew; /* sector 0 skew, per track */
233 /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
234 int32_t fs_id[2]; /* unique filesystem id */
235 /* sizes determined by number of cylinder groups and their sizes */
236 ufs_daddr_t fs_csaddr; /* blk addr of cyl grp summary area */
237 int32_t fs_cssize; /* size of cyl grp summary area */
238 int32_t fs_cgsize; /* cylinder group size */
239 /* these fields are derived from the hardware */
240 int32_t fs_ntrak; /* tracks per cylinder */
241 int32_t fs_nsect; /* sectors per track */
242 int32_t fs_spc; /* sectors per cylinder */
243 /* this comes from the disk driver partitioning */
244 int32_t fs_ncyl; /* cylinders in filesystem */
245 /* these fields can be computed from the others */
246 int32_t fs_cpg; /* cylinders per group */
247 int32_t fs_ipg; /* inodes per group */
248 int32_t fs_fpg; /* blocks per group * fs_frag */
249 /* this data must be re-computed after crashes */
250 struct csum fs_cstotal; /* cylinder summary information */
251 /* these fields are cleared at mount time */
252 int8_t fs_fmod; /* super block modified flag */
253 int8_t fs_clean; /* filesystem is clean flag */
254 int8_t fs_ronly; /* mounted read-only flag */
255 int8_t fs_flags; /* see FS_ flags below */
256 u_char fs_fsmnt[MAXMNTLEN]; /* name mounted on */
257 u_char fs_volname[MAXVOLLEN]; /* volume name */
258 u_int64_t fs_swuid; /* system-wide uid */
259 int32_t fs_pad; /* due to alignment of fs_swuid */
260 /* these fields retain the current block allocation info */
261 int32_t fs_cgrotor; /* last cg searched */
262 void *fs_ocsp[NOCSPTRS]; /* padding; was list of fs_cs buffers */
263 uint8_t *fs_contigdirs; /* # of contiguously allocated dirs */
264 struct csum *fs_csp; /* cg summary info buffer for fs_cs */
265 int32_t *fs_maxcluster; /* max cluster in each cyl group */
266 int32_t fs_cpc; /* cyl per cycle in postbl */
267 int16_t fs_opostbl[16][8]; /* old rotation block list head */
268 int32_t fs_snapinum[FSMAXSNAP];/* RESERVED FROM 5.x */
269 int32_t fs_avgfilesize; /* expected average file size */
270 int32_t fs_avgfpdir; /* expected # of files per directory */
271 int32_t fs_sparecon[26]; /* reserved for future constants */
272 int32_t fs_pendingblocks; /* RESERVED FROM 5.x */
273 int32_t fs_pendinginodes; /* RESERVED FROM 5.x */
274 int32_t fs_contigsumsize; /* size of cluster summary array */
275 int32_t fs_maxsymlinklen; /* max length of an internal symlink */
276 int32_t fs_inodefmt; /* format of on-disk inodes */
277 uint64_t fs_maxfilesize; /* maximum representable file size */
278 int64_t fs_qbmask; /* ~fs_bmask for use with 64-bit size */
279 int64_t fs_qfmask; /* ~fs_fmask for use with 64-bit size */
280 int32_t fs_state; /* validate fs_clean field */
281 int32_t fs_postblformat; /* format of positional layout tables */
282 int32_t fs_nrpos; /* number of rotational positions */
283 int32_t fs_postbloff; /* (uint16) rotation block list head */
284 int32_t fs_rotbloff; /* (uint8) blocks for each rotation */
285 int32_t fs_magic; /* magic number */
286 uint8_t fs_space[1]; /* list of blocks for each rotation */
287 /* actually longer */
291 * Filesystem identification
293 #define FS_MAGIC 0x011954 /* the fast filesystem magic number */
294 #define FS_OKAY 0x7c269d38 /* superblock checksum */
295 #define FS_42INODEFMT -1 /* 4.2BSD inode format */
296 #define FS_44INODEFMT 2 /* 4.4BSD inode format */
299 * Preference for optimization.
301 #define FS_OPTTIME 0 /* minimize allocation time */
302 #define FS_OPTSPACE 1 /* minimize disk fragmentation */
307 #define FS_UNCLEAN 0x01 /* filesystem not clean at mount */
308 #define FS_DOSOFTDEP 0x02 /* filesystem using soft dependencies */
311 * Rotational layout table format types
313 #define FS_42POSTBLFMT -1 /* 4.2BSD rotational table format */
314 #define FS_DYNAMICPOSTBLFMT 1 /* dynamic rotational table format */
316 * Macros for access to superblock array structures
318 #define fs_postbl(fs, cylno) \
319 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
320 ? ((fs)->fs_opostbl[cylno]) \
321 : ((int16_t *)((uint8_t *)(fs) + \
322 (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
323 #define fs_rotbl(fs) \
324 (((fs)->fs_postblformat == FS_42POSTBLFMT) \
326 : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_rotbloff)))
329 * The size of a cylinder group is calculated by CGSIZE. The maximum size
330 * is limited by the fact that cylinder groups are at most one block.
331 * Its size is derived from the size of the maps maintained in the
332 * cylinder group and the (struct cg) size.
335 /* base cg */ (sizeof(struct cg) + sizeof(int32_t) + \
336 /* blktot size */ (fs)->fs_cpg * sizeof(int32_t) + \
337 /* blks size */ (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
338 /* inode map */ howmany((fs)->fs_ipg, NBBY) + \
339 /* block map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
340 /* if present */ ((fs)->fs_contigsumsize <= 0 ? 0 : \
341 /* cluster sum */ (fs)->fs_contigsumsize * sizeof(int32_t) + \
342 /* cluster map */ howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
345 * Convert cylinder group to base address of its global summary info.
347 #define fs_cs(fs, indx) fs_csp[indx]
350 * Cylinder group block for a filesystem.
352 #define CG_MAGIC 0x090255
354 int32_t cg_firstfield; /* historic cyl groups linked list */
355 int32_t cg_magic; /* magic number */
356 ufs_time_t cg_time; /* time last written */
357 int32_t cg_cgx; /* we are the cgx'th cylinder group */
358 int16_t cg_ncyl; /* number of cyl's this cg */
359 int16_t cg_niblk; /* number of inode blocks this cg */
360 int32_t cg_ndblk; /* number of data blocks this cg */
361 struct csum cg_cs; /* cylinder summary information */
362 int32_t cg_rotor; /* position of last used block */
363 int32_t cg_frotor; /* position of last used frag */
364 int32_t cg_irotor; /* position of last used inode */
365 int32_t cg_frsum[MAXFRAG]; /* counts of available frags */
366 int32_t cg_btotoff; /* (int32) block totals per cylinder */
367 int32_t cg_boff; /* (uint16) free block positions */
368 int32_t cg_iusedoff; /* (uint8) used inode map */
369 int32_t cg_freeoff; /* (uint8) free block map */
370 int32_t cg_nextfreeoff; /* (uint8) next available space */
371 int32_t cg_clustersumoff; /* (uint32) counts of avail clusters */
372 int32_t cg_clusteroff; /* (uint8) free cluster map */
373 int32_t cg_nclusterblks; /* number of clusters this cg */
374 int32_t cg_sparecon[13]; /* reserved for future use */
375 uint8_t cg_space[1]; /* space for cylinder group maps */
376 /* actually longer */
380 * Macros for access to cylinder group array structures
382 #define cg_blktot(cgp) \
383 (((cgp)->cg_magic != CG_MAGIC) \
384 ? (((struct ocg *)(cgp))->cg_btot) \
385 : ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_btotoff)))
386 #define cg_blks(fs, cgp, cylno) \
387 (((cgp)->cg_magic != CG_MAGIC) \
388 ? (((struct ocg *)(cgp))->cg_b[cylno]) \
389 : ((int16_t *)((uint8_t *)(cgp) + \
390 (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
391 #define cg_inosused(cgp) \
392 (((cgp)->cg_magic != CG_MAGIC) \
393 ? (((struct ocg *)(cgp))->cg_iused) \
394 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_iusedoff)))
395 #define cg_blksfree(cgp) \
396 (((cgp)->cg_magic != CG_MAGIC) \
397 ? (((struct ocg *)(cgp))->cg_free) \
398 : ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_freeoff)))
399 #define cg_chkmagic(cgp) \
400 ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
401 #define cg_clustersfree(cgp) \
402 ((uint8_t *)((uint8_t *)(cgp) + (cgp)->cg_clusteroff))
403 #define cg_clustersum(cgp) \
404 ((int32_t *)((uint8_t *)(cgp) + (cgp)->cg_clustersumoff))
407 * The following structure is defined
408 * for compatibility with old filesystems.
411 int32_t cg_firstfield; /* historic linked list of cyl groups */
412 int32_t cg_unused_1; /* used for incore cyl groups */
413 ufs_time_t cg_time; /* time last written */
414 int32_t cg_cgx; /* we are the cgx'th cylinder group */
415 int16_t cg_ncyl; /* number of cyl's this cg */
416 int16_t cg_niblk; /* number of inode blocks this cg */
417 int32_t cg_ndblk; /* number of data blocks this cg */
418 struct csum cg_cs; /* cylinder summary information */
419 int32_t cg_rotor; /* position of last used block */
420 int32_t cg_frotor; /* position of last used frag */
421 int32_t cg_irotor; /* position of last used inode */
422 int32_t cg_frsum[8]; /* counts of available frags */
423 int32_t cg_btot[32]; /* block totals per cylinder */
424 int16_t cg_b[32][8]; /* positions of free blocks */
425 uint8_t cg_iused[256]; /* used inode map */
426 int32_t cg_magic; /* magic number */
427 uint8_t cg_free[1]; /* free block map */
428 /* actually longer */
432 * Turn filesystem block numbers into disk block addresses.
433 * This maps filesystem blocks to device size blocks.
435 #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
436 #define dbtofsb(fs, b) ((b) >> (fs)->fs_fsbtodb)
437 #define btofsb(fs, b) ((daddr_t)((b) >> ((fs)->fs_fsbtodb + DEV_BSHIFT)))
440 * Cylinder group macros to locate things in cylinder groups.
441 * They calc filesystem addresses of cylinder group data structures.
443 #define cgbase(fs, c) ((ufs_daddr_t)((fs)->fs_fpg * (c)))
444 #define cgdmin(fs, c) (cgstart(fs, c) + (fs)->fs_dblkno) /* 1st data */
445 #define cgimin(fs, c) (cgstart(fs, c) + (fs)->fs_iblkno) /* inode blk */
446 #define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno) /* super blk */
447 #define cgtod(fs, c) (cgstart(fs, c) + (fs)->fs_cblkno) /* cg block */
448 #define cgstart(fs, c) \
449 (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
452 * Macros for handling inode numbers:
453 * inode number to filesystem block offset.
454 * inode number to cylinder group number.
455 * inode number to filesystem block address.
457 #define ino_to_cg(fs, x) ((x) / (fs)->fs_ipg)
458 #define ino_to_fsba(fs, x) \
459 ((ufs_daddr_t)(cgimin(fs, ino_to_cg(fs, x)) + \
460 (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
461 #define ino_to_fsbo(fs, x) ((x) % INOPB(fs))
464 * Give cylinder group number for a filesystem block.
465 * Give cylinder group block number for a filesystem block.
467 #define dtog(fs, d) ((d) / (fs)->fs_fpg)
468 #define dtogd(fs, d) ((d) % (fs)->fs_fpg)
471 * Extract the bits for a block from a map.
472 * Compute the cylinder and rotational position of a cyl block addr.
474 #define blkmap(fs, map, loc) \
475 (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
476 #define cbtocylno(fs, bno) \
477 ((bno) * NSPF(fs) / (fs)->fs_spc)
478 #define cbtorpos(fs, bno) \
479 (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
480 (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
481 (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
484 * The following macros optimize certain frequently calculated
485 * quantities by using shifts and masks in place of divisions
486 * modulos and multiplications.
488 #define blkoff(fs, loc) /* calculates (loc % fs->fs_bsize) */ \
489 ((loc) & (fs)->fs_qbmask)
490 #define fragoff(fs, loc) /* calculates (loc % fs->fs_fsize) */ \
491 ((loc) & (fs)->fs_qfmask)
492 #define lblktosize(fs, blk) /* calculates ((off_t)blk * fs->fs_bsize) */ \
493 ((off_t)(blk) << (fs)->fs_bshift)
495 * These functions convert filesystem logical block numbers (typ 8K),
496 * filesystem block numbers (typ 1K), and disk block numbers to 64 bit
497 * offsets for the purposes of bread(), getblk(), etc.
499 * note: fs_nspf = number of sectors per fragment. For some reason
500 * completely lost to me the superblock doesn't actually store the disk
503 #define lblktodoff(fs, blk) ((off_t)(blk) << (fs)->fs_bshift)
504 #define fsbtodoff(fs, b) ((off_t)(b) << (fs)->fs_fshift)
505 #define dbtodoff(fs, b) ((off_t)(b) * ((fs)->fs_fsize / (fs)->fs_nspf))
506 #define dofftofsb(fs, b) ((ufs_daddr_t)((b) >> (fs)->fs_fshift))
508 /* Use this only when `blk' is known to be small, e.g., < NDADDR. */
509 #define smalllblktosize(fs, blk) /* calculates (blk * fs->fs_bsize) */ \
510 ((blk) << (fs)->fs_bshift)
511 #define lblkno(fs, loc) /* calculates (loc / fs->fs_bsize) */ \
512 ((loc) >> (fs)->fs_bshift)
513 #define numfrags(fs, loc) /* calculates (loc / fs->fs_fsize) */ \
514 ((loc) >> (fs)->fs_fshift)
515 #define blkroundup(fs, size) /* calculates roundup(size, fs->fs_bsize) */ \
516 (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
517 #define fragroundup(fs, size) /* calculates roundup(size, fs->fs_fsize) */ \
518 (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
519 #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
520 ((frags) >> (fs)->fs_fragshift)
521 #define blkstofrags(fs, blks) /* calculates (blks * fs->fs_frag) */ \
522 ((blks) << (fs)->fs_fragshift)
523 #define fragnum(fs, fsb) /* calculates (fsb % fs->fs_frag) */ \
524 ((fsb) & ((fs)->fs_frag - 1))
525 #define blknum(fs, fsb) /* calculates rounddown(fsb, fs->fs_frag) */ \
526 ((fsb) &~ ((fs)->fs_frag - 1))
529 * Determine the number of available frags given a
530 * percentage to hold in reserve.
532 #define freespace(fs, percentreserved) \
533 (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
534 (fs)->fs_cstotal.cs_nffree - \
535 ((off_t)((fs)->fs_dsize) * (percentreserved) / 100))
538 * Determining the size of a file block in the filesystem.
540 #define blksize(fs, ip, lbn) \
541 (((lbn) >= NDADDR || (ip)->i_size >= smalllblktosize(fs, (lbn) + 1)) \
543 : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
544 #define dblksize(fs, dip, lbn) \
545 (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
547 : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
548 #define sblksize(fs, size, lbn) \
549 (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
551 : (fragroundup(fs, blkoff(fs, (size)))))
554 * Extract the block size for the buffer cache buffer at offset (loc)
555 * relative to the current ip->i_size, or relative to a specific ip->i_size.
557 #define blkoffsize(fs, ip, loc) blksize(fs, ip, lblkno(fs, loc))
558 #define blkoffresize(fs, loc) sblksize(fs, loc, lblkno(fs, loc))
561 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
564 #define NSPB(fs) ((fs)->fs_nspf << (fs)->fs_fragshift)
565 #define NSPF(fs) ((fs)->fs_nspf)
568 * Number of inodes in a secondary storage block/fragment.
570 #define INOPB(fs) ((fs)->fs_inopb)
571 #define INOPF(fs) ((fs)->fs_inopb >> (fs)->fs_fragshift)
574 * Number of indirects in a filesystem block.
576 #define NINDIR(fs) ((fs)->fs_nindir)
578 extern int inside[], around[];
579 extern u_char *fragtbl[];
581 #endif /* !_VFS_UFS_FS_H_ */